APA 6th Edition Zuman, P. & Rupp, E.B. (2006). Humic Acids – Are They Natural Products?. Croatica Chemica Acta, 79 (1), 57-65. Retrieved from https://hrcak.srce.hr/2602
MLA 8th Edition Zuman, Petr and Elinore B. Rupp. "Humic Acids – Are They Natural Products?." Croatica Chemica Acta, vol. 79, no. 1, 2006, pp. 57-65. https://hrcak.srce.hr/2602. Accessed 13 Apr. 2021.
Chicago 17th Edition Zuman, Petr and Elinore B. Rupp. "Humic Acids – Are They Natural Products?." Croatica Chemica Acta 79, no. 1 (2006): 57-65. https://hrcak.srce.hr/2602
Harvard Zuman, P., and Rupp, E.B. (2006). 'Humic Acids – Are They Natural Products?', Croatica Chemica Acta, 79(1), pp. 57-65. Available at: https://hrcak.srce.hr/2602 (Accessed 13 April 2021)
Vancouver Zuman P, Rupp EB. Humic Acids – Are They Natural Products?. Croatica Chemica Acta [Internet]. 2006 [cited 2021 April 13];79(1):57-65. Available from: https://hrcak.srce.hr/2602
IEEE P. Zuman and E.B. Rupp, "Humic Acids – Are They Natural Products?", Croatica Chemica Acta, vol.79, no. 1, pp. 57-65, 2006. [Online]. Available: https://hrcak.srce.hr/2602. [Accessed: 13 April 2021]
Abstracts Alkaline cleavage of soil organic matter was studied by following the changes in absorbance at 250–270 nm, but particularly using differential pulse polarography. The measurement of peak currents obtained by the latter technique allowed to follow changes in concentration of CH3Oand HO-substituted benzaldehydes as well as of α,β-unsaturated ketones with time directly in the suspension of soil. Kinetics of the cleavage of the organic materials from soil and in particular its pH-dependence, were similar to that of cleavage of lignin, but different from those obtained with samples of humic acids. Based on this comparison and on discussion of chemical processes taking place during procedures used for isolation of humic acids from soils and waters, it is strongly indicated that humic acids are man-made macromolecular species rather than natural products.